Evaluation of Maillard Reaction intensity, Physical-chemistry Attributes and Texture Analysis in "Dulce de Leche"

ABSTRACT The Dulce de Leche, a product which is marketed and produced in Latin America, is much appreciated by consumers, with great importance for the Brazilian market. The standardization of the characteristics of this product as well as the suitability for recommendations of the Technical Identity and Quality Regulation becomes difficult due to the large cultural diversity and technological changes. In this context, the study of physical-chemical and rheological characteristics the Dulce de Leche becomes of great importance to achieve such uniformity, mainly by the lack of technical and scientific literature about this product. This work aimed to evaluate and relate the physical-chemical and texture attributes. Twelve Dulce de Leche brands were analyzed to moisture, water activity and texture analysis with statistical analysis of the data. Descriptive statistical analysis for texture attributes showed high variability between samples. As for the moisture content, 51.11% of the samples were outside the statutory standards. The analysis had results of free HMF and elevated totals. Through the Principal Component Analysis (PCA) it was found that the main source of variation and contribution to group of the appraised brands is related to the elements that make up the rheological characteristics of the product. The results showed high correlation between water activity, moisture and rheological attributes. The combination of physical, chemical and rheological attributes were shown to be useful for characterization and evaluation of Dulce de Leche quality. These results expand scientific knowledge about Dulce de leche favoring the dairy industry and the scientific community.

摘要
焦糖牛乳酱（Dulce de Leche）是拉丁美洲产销的特色食品，深受消费者喜爱，在巴西市场占据重要地位。由于文化多样性较高且技术迭代较快，该产品的特性标准化以及《技术标识与质量法规》推荐要求的合规性落实均存在较大难度。在此背景下，针对焦糖牛乳酱的理化与流变学特性开展研究，对实现产品特性统一具有重要意义——当前针对该产品的专业技术与科学文献仍较为匮乏。
本研究旨在对其理化与质构特性进行评估并分析二者的关联。研究选取12个品牌的焦糖牛乳酱样品，对其水分含量、水分活度及质构特性开展检测，并对所得数据进行统计学分析。质构特性的描述性统计分析结果显示，各样品间存在较高的变异性。水分含量方面，51.11%的样品不符合法定标准。检测结果显示样品游离羟甲基糠醛（HMF）含量偏高，总羟甲基糠醛含量亦超出合理范围。通过主成分分析（PCA）可知，受试品牌样品的主要变异来源与样品分组依据，均与构成产品流变学特性的各项参数密切相关。研究结果表明，水分活度、水分含量与流变学特性三者间存在显著相关性。理化与流变学特性的组合检测方法，可有效用于焦糖牛乳酱的品质表征与质量评估。本研究结果拓展了焦糖牛乳酱相关的科学认知，可为乳制品行业与科研群体提供有益支撑。